Dye and heat sensitive transfer material comprising the same

ABSTRACT

An image forming dye and a heat sensitive transfer material comprising the same are disclosed, the dye being represented by the following Formula (1): ##STR1##

This is a division of application Ser. No. 08/212,003 filed Mar. 11,1994.

FIELD OF THE INVENTION

The present invention relates to a novel dye for an image forming dyeusable in an image forming method using a heat sensitive transfermaterial, a photographic light sensitive material or an ink jet imageforming material. More specifically, the present invention relates to adye improved in image preservability and absorption characteristics anda heat sensitive transfer material using the dye.

BACKGROUND OF THE INVENTION

As a simple dry process for obtaining images, particularly full colorimages, there is known a method which uses a heat sensitive transfermaterial. In such a heat sensitive material, a dye used to form colorimages is of especial importance, and there have been proposed a varietyof dyes for this purpose. The dye for color image formation is requiredto have good absorption characteristics including a sharp spectralabsorption less in secondary absorption and a high spectral absorptioncoefficient as well as high stabilities to heat and light. Further, itis also important that the dye can be easily synthesized and readilydissolved in a solvent. Japanese Pat. O.P.I. Pub. No. 63194/1989proposes a heat transfer material which uses a specific magenta dye. Theheat sensitive transfer material which uses the dye disclosed in theabove patent can form images of good hue and, further, has a highsensitivity because the dye itself has a high molar absorptioncoefficient, so that the pending problems of heat sensitive imagetransfer can be solved in those respects. However, it has a defect thatthe light fastness of images is considerably low. With the object ofeliminating the defect in light fastness, Japanese Pat. O.P.I. Pub. No.178646/1992 proposes a pyrazoloazole azomethine dye having a specificatomic group in its dye structure and a heat sensitive transfer materialusing the dye. However, the dye disclosed in said patent hasdisadvantages that its synthesis needs a complicated procedure and thatwhen used in a heat sensitive material, it lowers the sensitivitybecause of its large molecular weight due to an atomic group introducedinto it.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 shows spectral absorption spectra of dye D-1 of the invention.

FIG. 2 shows spectral absorption spectra of dye D-2 of the invention.

SUMMARY OF THE INVENTION

Accordingly, the subject of the present invention is to improve theexisting technique on the matter.

It is an object of the present invention to provide not only a dyeexcellent in stabilities to heat and light but also a heat sensitivetransfer material using the dye.

It is a further object of the present invention to provide not only adye sharp in spectral absorption, less in secondary absorption and highin spectral absorption coefficient but also a heat sensitive transfermaterial using the dye.

It is a still another object of the present invention to provide a dyewhich can be easily synthesized and readily dissolved in a solvent.

As a result of studies, the present inventors have found that the aboveobjects of the invention are attained by the following constituents:

1. A dye represented by the following Formula (1): ##STR2## wherein Xrepresents a N(R₃)(R₄) group or a hydroxyl group, wherein R₃ and R₄ maybe same or different and independently represent a substituted orunsubstituted alkyl alkenyl, aryl, aralkyl or cycloalkyl group, providedthat R₃ and R₄ may combine with each other or with R₁ to form a ring; Y₁and Y₂ independently represent a carbon atom or a nitrogen atom,provided that one of Y₁ and Y₂ is a nitrogen atom; Z represents anatomic group necessary to form a substituted or unsubstituted 5- or6-membered nitrogen-containing heterocyclic ring which may be condensedwith another ring; R₁ represents a hydrogen atom, a halogen atom or amonovalent substituent; R₂ represents a monovalent substituent, providedthat one of R₂ and a substituent on the ring represented by Z has aHammett's value of not less than -0.05.

2. A heat sensitive transfer material comprising a support and providedthereon a layer containing a dye and a binder, wherein the dye isrepresented by the above Formula (1).

DETAILED DESCRIPTION OF THE INVENTION

The compound represented by Formula (1) is described in more detail.

X represents a N(R₃)(R₄) group or a hydroxyl group, wherein R₃ and R₄independently represent an alkyl group (e.g., methyl, ethyl, propyl), analkenyl group (e.g., propenyl), an aryl group (e.g., phenyl), an aralkylgroup (e.g., benzyl), a cycloalkyl group (e.g., cyclohexyl,cyclopentyl), provided that R₃ and R₄ may combine with each other orwith R₁ to form a ring; but, X is preferably a N(R₃)(R₄) group whereinboth R₃ and R₄ are substituted or unsubstituted lower alkyl groups.Examples of the substituent include a hydroxyl group, an alkoxy group, acyano group, an alkylsulfonylamino group or a halogen atom. Further, R₃and R₄, or R₃ and R₁, may combine with each other to form a 5- or6-membered ring. R₁ represents a hydrogen atom, a halogen atom (e.g.,fluorine, chlorine) or a monovalent group, wherein the monovalent groupis a substituted or unsubstituted alkyl group, cycloalkyl group, alkoxygroup, aryl group, aryloxy group, aralkyl group, acylamino group,sulfonylamino group, ureido group, alkylthio group, alkoxycarbonylgroup, carbamoyl group, acyl group, amino group, sulfonyl group,sulfamoyl group or alkoxycarbonyl group, and preferably an alkyl groupor an alkoxy group. R₂ represents a monovalent substituent such as analkyl group, a cycloalkyl group, an alkoxy group, an aryl group, anaryloxy group, an aralkyl group, an acyl group, a sulfonylamino group, aureido group, an alkylthio group, an alkoxycarbonyl group, a carbamoylgroup, an acyl group, an amino group, a cyano group, an alkylsulfonylgroup, an alkylsulfinyl group, a sulfamoyl group or an alkoxycarbonylgroup, each of which may have a substituent. Further, at least one of R₂and the substituents on the ring represented by Z is a substituenthaving a Hammett's value not less than -0.05; examples thereof includean aryl group (e.g., phenyl), a halogen-substituted alkyl group (e.g.,trifluoromethyl, trichloromethyl, tetrafluoroethyl), a cyano group, analkylsulfonyl group (e.g., methanesulfonyl), an alkylsulfinyl group(e.g., methanesulfinyl), a sulfamoyt group (e.g., diethylsulfamoyl), acarbamoyl group (e.g., diethylcarbamoyl) and an alkoxycarbonyl (e.g.,methoxycarbonyl). Among the dyes represented by Formula (1),particularly preferred is a dye represented by the following Formula (2)or (3): ##STR3## wherein R₁, R₂, X, Y₁ and Y₂ independently representthe same as those defined in formula (1); and R₅ is selected from thegroup consisting of an alkyl group, a cycloalkyl group, an alkoxy group,an aryl group, an aryloxy group, an aralkyl group, an acylamino group, asulfonylamino group, a ureido group, an alkylthio group, analkoxycarbonyl group, a carbamoyl group, an acyl group, an amino group,a cyano group, an alkylsulfonyl group, an alkylsulfinyl group or asulfamoyl group each of which may have a substituent, provided that oneof R₂ and R₅ has a Hammett's value of not less than -0.05. Examples ofR₂ or R₅ in Formulas (2) and (3) are selected from the group consistingof an aryl group (e.g., phenyl), a halogen substituted alkyl group(e.g.,trifluoromethyl, trichloromethyl, tetra-fluoroethyl), a cyano group, analkylsulfonyl group (e.g., methanesulfonyl), an alkylsulfinyl group(e.g., methanesulfinyl), a sulfamoyl group (e.g., diethylsulfamoyl), acarbamoyl group (e.g., diethylcarbamoyl) and an alkoxycarbonyl group(e.g., methoxycarbonyl).

The Hammett's value of the present invention is described on pages 99 to121 of "Kagaku no Ryouiki", Extra number 122nd published by Nankodo onMar. 1, 1980.

In view of obtaining a satisfactory sensitivity, storage stability andsolubility, it is preferred that the dye of the invention has amolecular weight of 350 to 550 when used in a heat sensitive transfermaterial.

Typical examples of the dyes of the invention include the followingcompounds: ##STR4##

The dye of the invention is prepared by coupling reaction of a couplerwith a compound represented by formula (5) in an aqueous or organicsolvent solution under an alkaline condition in the presence of anoxidizing agent. The organic solvent includes methanol, ethanol,ethylacetate, tetrahydrofuran, dimethylformamide, acetone, toluene oracetonitrile. Methanol or ethylacetate is preferably used. The alkaliagent includes an organic or inorganic alkali agent, for example,pyridine, triethylamine, dimethylaniline, sodium hydroxide, potassiumhydroxyde, sodium carbonate, potassium carbonate, sodium bicarbonate,potassium bicarbonate or sodium acetate. Triethylamine, potassiumhydroxyde or potassium carbonate is preferably used. The oxidizing agentincludes silver oxide, potassium persulfate, ammonium persulfate,potassium ferricyanide, hydrogen peroxide or sodium chlorite. Potassiumpersulfate or ammonium persulfate is preferably used. ##STR5##

The coupler represented by formula (4) is prepared by a method describedin Japanese Patent O.P.I. Publication Nos. 63-231341/1988 and2-201443/1991.

The compound represented by formula (5) is prepared by the methoddescribed below (Route 1). ##STR6##

The intermediate compounds (7) and (8) having a nitro group aresynthesized by the method described in Chem. Ber.,85, 1012 (1952) orJ.Am.Chem.Soc., 74 (1952)3828. The intermediate compound (8) having anitro group is also synthesized by reacting compound (6) with an alkylhalide in a solvent such as xylene or toluene in the presence of a basesuch as NaNH₂ or NaH to obtain a mono or di-alkylated amino compound andnitrating the alkylated amino compound. The nitration is carried out bythe well-known method or preferably by using nitric acid having agravity of 1.38 to 1.52/surfuric acid and/or acetic acid. It ispreferable that the amount used of nitric acid is 0.8 to 1.8 times bymole that of the dialkylated compound and the reaction temperature is-10° to 20° C. ##STR7##

The Compounds (7) and (8) are reduced by a hydrogen reduction (using acatalyst, Pd/C or Raney Nickel) under an atmospheric pressure orincreased pressure or a chemical reduction (reduced iron/acetic acid,tin/hydrochloride or hydrosulfite/methanol-water to obtain compounds (9)and (10).

Next, the heat sensitive transfer material using the dye of theinvention is described. The heat sensitive transfer material has, on asupport, a dye-containing layer comprising at least a dye and a binder.

The content of the dye is preferably 0.05 to 10 g per m² of the support.Preferred binders are solvent-soluble polymers such as acrylate resins,methacrylate resins, polystyrenes, polycarbonates, polysulfones,polyether sulfones, polyvinyl butyrals, polyvinyl acetals,nitrocetlulose, ethyl cellulose and the likes. These binders may beused, singly or in combination of two or more kinds, by being dissolvedin an organic solvent or in the form of a dispersion as latex.Preferably, these binders are used in an amount of 0.1 to 20 g per m² ofthe support. The dye-containing layer can be formed by coating, on asupport, an ink for the formation of heat sensitive transfer layerprepared by dissolving a dye and a binder in a solvent, or by dispersingthem in a solvent into fine particles, and then drying the coated ink.The dry thickness of the dye-containing layer is preferably 1 to 10 μm.The support used in the invention may be any of the conventional ones aslong as it has a good dimensional stability and can withstand the heatapplied by a thermal head during recording; preferred are tissue papersuch as condenser paper and glassine paper, and films of heat-resistantplastics such as polyethylene terephthalates, polyamides andpolycarbonates. The thickness of the support is preferably 2 to 30 μm.In order to improve adhesion of the support to the binder and to preventthe dye from transferring or migrating to the support, it is preferredthat a subbing layer comprising a selected polymer be provided. Further,a slipping layer may be provided on the reverse side of the support(oppositely with the dye-containing layer) in order to prevent a thermalhead from sticking to the support. In applying the heat sensitivetransfer material of the invention to a heat sensitive transfer materialfor full color image recording, it is preferred that a yellow heatsensitive transfer layer containing a yellow dye, a magenta heatsensitive transfer layer containing the magenta dye of the invention anda cyan heat sensitive transfer layer containing a cyan dye, three layersin total, be repeatedly coated in order on the same surface of thesupport. If necessary, four heat sensitive layers comprising a blackimage forming layer and the above three layers may be repeatedly coatedin order on the same surface of the support. In carrying out imagerecording by use of the heat sensitive transfer material of theinvention, the dye-containing layer of the heat sensitive transfermaterial is superposed on an image receiving material, and then heat isapplied, correspondingly to image information, to the heat sensitivetransfer material to form an image on the image receiving material, andthen the image receiving material is separated from the heat sensitivetransfer material. As the image receiving material, use is made of onecomprising a support having thereon an image receiving layer. Preferredsupports for the image receiving material include paper, plastic filmsand paper-plastic film composites.

Typical examples of the support include those described from the 17thline in the upper right column to the 11th line of the lower left columnon page 5 of the specification of Japanese Pat. O.P.I. Pub. No.54556/1991. The image receiving layer is made of a polymer binder.Preferred polymer binders are thermoplastic polymers such as polyesterresins, polyvinyl chloride resins, copolymers of vinyl chloride withother monomers (e.g., vinyl acetate, etc.), polyvinyl butyrals,polyvinyl pyrrolidones and polycarbonates, and these are formed into apolymer layer singly or in combination of two or more kinds.

Besides the utilization in heat sensitive transfer materials, the dye ofthe invention can be used in other image forming materials includingthose for ink jet type as well as in image display materials includingcolor filters.

EXAMPLES

The invention is described in detail with the following examples, butthe embodiment of the invention is not limited to them.

Example 1 Synthesis and Evaluation of Dye

1. Synthesis of Dye D-1

Synthesis of Intermediate (A) ##STR8##

To 100 ml of acetonitrile was added 10.6 g of5-t-butyl-2-hydrazinothiadiazine, and further 10 g of anhydroustrifluoroacetic acid was added with stirring, the reaction liquor wasthen stirred for 1 hour. After distilling away acetonitrile, ethylacetate was added to obtain an ethyl acetate solution. The ethyl acetatesolution was washed with water and with an aqueous solution of sodiumcarbonate and then separated and dried. Removal of the ethyl acetate bydistillation gave 12.4 g of intermediate (A).

Synthesis of Coupler (A) ##STR9##

A mixture of 12 g of intermediate (A) and 50 ml of acetic anhydride wasstirred for 30 hours. After distilling away the solvent, 100 ml ofmethanol and 10 ml of concentrated. hydrochloric acid were added, andthe reaction liquor was stirred for 2 hours, followed by suctionfiltration. Ethyl acetate and a saturated saline solution were added tothe filtrate. The ethyl acetate solution was separated, washed furtherwith an aqueous solution of sodium hydrogencarbonate and with thesaturated saline solution and dried, followed by removal of the ethylacetate by distillation. Thus, 7.2 g of coupler (A) was obtained.

Synthesis of Dye D-1

To a mixture of 4.0 g of coupler (A) and 200 ml of methanol was added3.1 g of 2-methyl-3-amino-6-N,N-diethylaminopyridine, and further 20 mlof an aqueous solution containing 9.1 g of sodium carbonate was addedwith stirring. Then, 20 ml of an aqueous solution containing 4.3 g ofammonium persulfate was added dropwise, followed by a 2-hour stirring.After depositing crystals by adding water thereto, the resultingcrystals were filtered out and recrystallized from acetonitrile, so that13.5 g of dye D-1 was obtained; the melting point was 143° to 145° C.

2. Synthesis of Dye D-2

Synthesis of Intermediate (B) ##STR10##

To an acetonitrile solution containing 30 g of5-t-butyl-2-hydrazinothiadiazine was added dropwise at room temperaturea mixed solution containing 21 g of benzyl chloride and 50 ml ofacetonitrile, the reaction liquor was stirred further for 2 hours.

The reaction liquor was filtered and, after concentrating the filtrate,ethyl acetate was added. The resulting crystals were filtered out,washed with ethyl acetate. Intermediate (B) was thus prepared in a yieldof 27.6 g.

Synthesis of Dye D-2 ##STR11##

Using 27 g of intermediate (B), coupler (B) was synthesized in a yieldof 14.5 g in a manner similar to that of coupler (A). Subsequently, 4.7g of dye D-2 was obtained from 5.0 g of coupler (B) in a manner similarto that of dye D-1. The melting point of the dye was 199° to 201° C. Theabsorption spectra of dyes D-1 and D-2 in acetone solutions are shown inFIG. 1, where the absorbance is plotted as axis of ordinate and thewavelength as axis of abscissa.

In FIG. 1, 1 designates a spectral absorption curve of dye D1 and 2designates a spectral absorption curve of dye D2.

The molar absorption coefficients of dyes D-1 and D-2 were 52300 and44000, respectively.

That is, the dyes of the invention have excellent spectral absorptioncharacteristics as magenta dyes and also have large molar absorptioncoefficients. In addition, these can be easily synthesized.

The chemical structure of the resulting dyes was confirmed as shownbelow by nmr and mass.

Dye D-1:

As a result of mass measurement, M⁺ was 416.

Results of nmr measurement are as follows (CDCl₃): δ(ppm): 1.25 (t 6H),1.60 (s 9H), 2.70 (s 3H), 3.65 (q 4H), 6.63 (d 1H), 7.50 (m 3H), 8.37 (d2H), and 9.53 (d 1H)

Dye D-2:

As a result of mass measurement, M⁺ was 408.

Results of nmr measurement are as follows (CDCl₃): δ(ppm): 1.28 (t 6H),1.58 (s 9H), 2.70 (s 3H), 3.50 (q 4H), 6.68 (d 1H) and 9.43 (d 1H)

    ______________________________________                                        Analytical measurement of elements                                                           Calculated value %                                                                           Obserbed value %                                ______________________________________                                        Dye D-1 C:     56.01          55.9                                                    H:     5.93           6.1                                                     N:     24.06          23.8                                                    F:     14.00          14.2                                            Dye D-2 C:     69.37          70.2                                                    H:     7.03           7.1                                                     N:     23.60          22.7                                            ______________________________________                                    

The spectral absorbance curves of Dyes D-1 and D-2 shown in FIG. 1 weremeasured by the use of an HITACHI automatic recording type spectralphotometer Model U-3300 produced by Hitachi Seisakusho Co., Ltd.

Example 2 Preparation of Heat Sensitive Transfer Material and ImageEvaluation

Preparation of Ink

A uniform ink solution containing the dye of the invention was obtainedby mixing the following materials:

    ______________________________________                                        Dye (D-1)                 5      g                                            Polyvinyl butyral resin                                                       (BL-1 made by Sekisui Chemical Co., Ltd)                                                                5      g                                            Methyl ethyl ketone       200    ml                                           ______________________________________                                    

Preparation of Heat Sensitive Transfer Material

Heat sensitive transfer material-1 comprising a polyethyleneterephthalate film having thereon a heat sensitive transfer layer wasprepared by coating the above ink with a wire bar on a 4.5 -μm thickpolyethylene terephthalate base and drying the ink so as to give a drycoating thickness of 0.8 g/m². Further, a nitrocellulose layercontaining a silicone-modified urethane resin (SP-2105 made byDainichiseika Co., Ltd.) was provided, as an antisticking layer, on theopposite side to the transfer layer of the film.

Preparation of Image Receiving Material

Image receiving material-1 was prepared by coating, as an imagereceiving layer, a methyl ethyl ketone solution of polyester resincontaining an ester-modified silicone (coating weight: 0.15 g/m²), onone side (laminated with polyethylene containing a white pigment (TiO₂)and a bluing agent) of a paper support laminated with polyethylene onboth sides, so as to give a polyester resin coating weight of 5 g/m².

Formation of Heat Sensitive Transfer Image

Heat sensitive transfer material-1 was superposed on image receivingmaterial-1, and an image recording was performed under the followingconditions by applying a thermal head to the reverse side of the heatsensitive transfer material. A magenta image (image-1) of excellentgradation was obtained.

The maximum density of the image is shown in Table 1.

Recording Conditions

Recording densities in primary scanning and secondary scanning: 8dots/mm

Recording power: 0.6 W/dot

Heating time: heating time was adjusted stepwise within the range of 20msec to 0.2 msec.

Heat sensitive transfer materials-2 to 7 and comparative heat sensitivetransfer materials-8 to 10 were prepared by repeating the procedure ofheat sensitive transfer material-1, except that a dye in heat sensitivetransfer material-1 was changed to dyes shown in Table 1. Images-2 to 10were formed in the same manner as in image-1; densities of those imagesare shown in Table 1.

Evaluation of Light Fastness

The images obtained were irradiated with light in a xenon fadeometer toexamine light fastness. With regard to evaluation on light-fastnessshown in Example 2, the density before and after exposing the resultingimages to 100 K_(J) using a Xenon Fade-O-Meter Model WEL-6X-HC-EC with 7kw (produced by Suga) was measured using an X-rite 310 (produced byX-rite Co., Ltd.). Residual dye rates after irradiation, which werecalculated by the equation D/D₀ ×100 (wherein D₀ is a density beforeirradiation of light), are shown in Table 1. The chemical structures ofdyes A, B and C listed in Table 1 are shown later. Dye A is described injapanese Patent O.P.I. Publication No. 64/63194/1989, dye B in JapanesePatent O.P.I. Publication No. 4/178,646/1992, and dye C in JapanesePatent O.P.I. Publication No. 4/89,287/1992.

Evaluation of Storage Stability of Heat Sensitive Transfer Material

                                      TABLE 1                                     __________________________________________________________________________            Substituent           Residual                                        Dye     (σp value)  Dmax                                                                              Dye rate                                                                           Remarks                                    __________________________________________________________________________    Image-1                                                                            D-1                                                                              CF.sub.3    (0.54)                                                                              2.28                                                                              85%  Invention                                  Image-2                                                                            D-2                                                                               ##STR12##  (-0.01)                                                                             2.20                                                                              89%  Invention                                  Image-3                                                                            D-3                                                                               ##STR13##  (>-0.01)                                                                            2.12                                                                              82%  Invention                                  Image-4                                                                            D-5                                                                              CF.sub.3    (0.54)                                                                              2.18                                                                              86%  Invention                                  Image-5                                                                            D-9                                                                               ##STR14##  (-0.01)                                                                             2.19                                                                              88%  Invention                                  Image-6                                                                            D-20                                                                             CF.sub.3    (0.54)                                                                              1.98                                                                              81%  Invention                                  Image-7                                                                            D-22                                                                              ##STR15##  (>-0.01)                                                                            2.16                                                                              82%  Invention                                  Image-8                                                                            A  --                2.12                                                                              29%  Comparative                                Image-9                                                                            B  --                1.36                                                                              89%  Comparative                                Image-10                                                                           C  C.sub.2 H.sub.5                                                                           (-0.15)                                                                             1.96                                                                              75%  Comparative                                        C(CH.sub.3).sub.3                                                                         (-0.20)                                                   __________________________________________________________________________    Dye A                                                                          ##STR16##                                                                    Dye B                                                                          ##STR17##                                                                    Dye C                                                                          ##STR18##                                                                    __________________________________________________________________________

Incidentally, the color of image-10 (comparative sample-10) was notmagenta but orange.

As is shown in Table 1, the heat sensitive transfer materials using thedyes of the invention can provide not only higher image densities ascompared with comparative material-9 (image-9) but also better lightfastnesses as compared with comparative material-8 (image-8), because oftheir superior dye transferring properties.

Moreover, the images formed by use of the materials of the inventionwere excellent in magenta tone. As is apparent from the above, the dyesof the invention each have a large absorption coefficient, a sharpabsorption less in secondary absorption and a good light fastness.Accordingly, the dyes of the invention can exhibit excellent propertieswhen used in image-forming materials including heat sensitive transfermaterials.

What is claimed is:
 1. A heat sensitive transfer material comprising asupport and provided thereon, a dye layer containing a dye and a binder,wherein said dye is selected from the group consisting of: ##STR19## 2.The heat sensitive transfer material of claim 1, wherein said dye layerhas a thickness of 1 to 10 μm.
 3. The heat sensitive transfer materialof claim 1, wherein said support has a thickness of 2 to 30 μm.
 4. Theheat sensitive transfer material of claim 1 wherein the dye is dye D-1.5. The heat sensitive transfer material of claim 1 wherein the dye isdye D-2.
 6. The heat sensitive transfer material of claim 1 wherein thedye is dye D-3.
 7. The heat sensitive transfer material of claim 1wherein the dye is dye D-5.
 8. The heat sensitive transfer material ofclaim 1, wherein the dye is dye D-9.
 9. The heat sensitive transfermaterial of claim 1 wherein the dye is dye D-22.
 10. A process offorming a thermal transfer image comprising the steps of:(a) superposinga dye layer of a heat sensitive transfer material on an image receivinglayer of an image receiving material, the heat sensitive transfermaterial comprising a support and provided thereon, the dye layercontaining a dye and a binder, (b) applying imagewise heat to the heatsensitive transfer material to produce an image in the image receivinglayer; and (c) separating the heat sensitive transfer material from theimage receiving material,wherein the dye is selected from the groupconsisting of: ##STR20##